1. Field of the Invention
This invention relates to a modular plug for terminating a cord having a non-planar array of conductors, and more particularly, to a plug that is specially suited to terminating a telephone cord having a generally circularly configured cross-section to facilitate connection of the cord to modular jacks in communications equipment.
2. Prior Art
Telephone cords which connect a telephone base to a telephone handset and the base to a wall terminal are known. These cords typically include a plurality of individually insulated electrical conductors and a plastic jacket enclosing the conductors. In the past, telephone cords were constructed with a cross-section of the cord being circularly configured and were terminated with flat connectors referred to as spade tips. See, for example, U.S. Pat. No. 2,609,417 issued Sept. 2, 1952 in the name of T. K. Cox et al.
The connection of spade-tip terminated cords to telephone apparatus and to wall terminals is accomplished by installers. Hence, the cost of changing such cords and installing telephones equipped with such cords must include charges for services performed by the installers at the customer's premises.
In order to expedite the replacement of telephone cords or the installation of telephone apparatus which in a growing number of areas are available at PhoneCenter stores, a "modular" system of telephone set components has been introduced. This system employs wall terminals and telephone apparatus with jacks which are adapted to receive modular plugs. Modular plugs and jacks are shown, for example, in U.S. Pat. Nos. 3,699,498 and 3,761,869 issued Oct. 17, 1972 and Sept. 25, 1973, respectively, both in the names of E. C. Hardesty, C. L. Krumreich, A. E. Mulbarger, Jr. and S. W. Walden, both of which are incorporated by reference hereinto. Telephone cords, both straight and retractile, are now terminated with modular plugs which preferably provide a side-by-side array of conductors, with terminals being aligned longitudinally with the axes of the conductors.
Modular plugs are designed to permit a subscriber to insert a plug into a jack and/or to remove the plug from the jack. This provides the customer with the capability of changing cords and/or installing additional telephones with existing wall terminals. Because of the ease with which telephone handsets may be connected to and disconnected from wall terminals, the handsets become portable. Still further, the customer may disconnect a retractile cord to remove kinks and then reconnect the cord.
The system of modularity also employs cordage with individually insulated conductors arranged in a side-by-side planar array. Such an arrangement, referred to as a "flat" cord, facilitates the assembly of a plug to a cord since an assembler need not orient the conductors individually prior to assembly with the plug. Also, "flat" cord insulated conductors are substantially smaller in diameter than insulated conductors used to construct the priorly manufactured circularly configured cords.
When refurbishing priorly made circularly configured cords, there has been a desire to terminate the refurbished cord with modular plugs. However, the plug which is being used to terminate the "flat" cords and shown for example, in U.S. Pat. No. 3,860,316, issued Jan. 14, 1975 in the name of E. C. Hardesty, and incorporated by reference hereinto, is not adapted to be assembled to cords having a non-planar array of conductors as is typical of the prior style cords. This incompatibility exists because the conductors of the prior style cord are considerably larger than those of the "flat" cord. A side-by-side arrangement is not possible if the spacing of the terminals which connect the conductors to components in the jack is maintained.
It is an object of this invention to provide modular plugs specially suited to terminating telephone cords having a generally circular configuration.
A further object is to provide a plug for terminating circularly configured cords and having provisions for supporting securely the terminals in an armed position with contact portions of the terminals spaced above the cord conductors for shipment to the field, whereupon the terminals may be driven into a fully seated position in engagement with cord conductors after a cord end has been inserted into the plug.
Connectors in which terminals are preassembled and partially seated in a housing transversely of a side-by-side array of conductors are shown in U.S. Pat. Nos. 3,812,449 and 3,890,029. Modular plugs which are armed with terminals for terminating "flat" cords are disclosed in application Ser. No. 620,629 filed Oct. 6, 1975 in the name of E. C. Hardesty, all of which are incorporated by reference hereinto, and commonly assigned.